The main objectives of this proposalare to produce Copenhagen line 2331 x Fischer 344, F1 hybrid male rats bearing R3327, a prostatic adenocarcinoma. The inoculated animals will be provided to investigators in the National Prostatic Cancer Project and extra material will be retained as a resource of frozen R3327 for in vitro studies. The plan is to maintain our production of f(1) hybrids at 75 male rats/week. The rats will be inoculated with r3327 and used in research projects relating to human prostatic cancer. Additional tumor lines of R3327 (squamous carcinoma and non-hormone responsive adenocarcinoma) will be maintained for comparative studies. A central respostory will enable the National Prostatic Cancer Project to explore other models as they become available.